Currently available commercial wireless communications devices generally all utilize a single antenna for reception. Currently proposed wireless local area network (WLAN) standards, such as the Institute for Electrical and Electronic Engineers (IEEE) 802.11a and European Tele-communications Standards Institute (ETSI) High Performance European Radio Local Area Network version 2 (HiperLAN2) standards, suggest antenna switching and diversity combining techniques to overcome typical channel fading problems in wireless systems. The antenna switching techniques normally select a signal from among various antenna based on the criteria of signal amplitude, while diversity combining utilizes the signals from each antenna by applying different weights. At least in theory, diversity combining produces better results than switching systems.
However, all currently published proposals for diversity combining or beamforming for coded orthogonal frequency division multiplexing (COFDM) systems employ algorithms operating at the symbol level, which fails to take maximum advantage of the one of the most important benefits of COFDM signaling: that equalization is embedded in the decoding process.
There is, therefore, a need in the art for bit-level diversity combining for coded orthogonal frequency division multiplexing receivers.